Machine gun with a mount for reducing the recoil forces applied to the trunnions



May 9, 1967 F. P. REED 3,3118fll9fi MACHINE GUN WITH A MOUNT FOR REDUCING THE RECOIL FORCES APPLIED TO THE TRUNNIONS Filed July 9, 1965 5 Sheets-Sheet 1 INVENTOR Q [q FrEflEriukEREEii ATTORNEY y 9, 1967 F P. REED ,11911 MACHINE GUN WITH A MOUNT FOR REDUCING THE RECOIL FORCES APPLIED TO THE TRUNNIONS Filed July 9, 1965 5 Sheets-Sheet 2 ATTORNEY May 9, 1967 F. P. REED 3,3WJM MACHINE GUN WITH A MOUNT FOR REDUCING THE RECOIL FORCES APPLIED TO THE TRUNNIONS 5 Sheets-Sheet 3 Filed July 9, 1965 iNVENTOR Preflerick EREEEL a r ATTORNEY F. P. REED MACHINE GUN WITH A MOUNT FOR REDUCING THE REC THE TRUNNIONS FORCES APPLIED TO Filed July 9, 1965 5 Sheets-Sheet 4.

ATTORNEY INVENTOR FIEflEIiGk P EEEa M47 SW11.

M y 1%? F. P. REED I 3311mm MACHINE GUN WITH A MOUNT FOR REDUCING THE RECOIL FORCES APPLIED TO THE TRUNNIONS Filed July 9, 1965 5 Sheets-Sheet 5 fiE AIEED poarrnom Figi 4s 42 34 SEARED POSITION FIRING POSITION L; W 1:? I 20 SEA'IEED POSITION mvENToR 43 FIEEIETiBkRREEEI. SEAREID POEITIQN IBY I 3 318,191 MACHXNE GUN Wli'iH A MOUNT FOR REDUCHNG THE RECQIL FURCES APPLIED TO THE TRUN- NEGNS Frederick ll". Reed, Ludlow, Mass assignor to the United States of America as represented by the Secretary of the Army Filed July 9, 1965, Ser. No. 470,942 4 Claims. (6i. 89-42) ABSTRAET OF THE DliSClLQSURE This invention provides a machine gun mount comprising a nonrecoiling cradle with mounting trunnions and a recoiling machine gun slidingly mounted on the cradle for displacement thereon responsive to recoil forces. A pair of sears releasably secure the machine gun to the cradle in the recoil position each firing cycle against the force of compressed butter springs. Solenoid actuated sear locks release the sears after cartridge feeding has taken place and in time to apply the energy in the compressed buffer springs, through forward motion of the machine gun, against the recoil force produced in the machine gun by the discharge of a cartridge therein to reduce the recoil force transmitted to the trunnions of the cradle.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to machine guns and pertains more particularly to the mountings thereof.

In modern ordnance, helicopters are being armed with machine guns, which creates problems as helicopters are susceptible to the recoil forces produced when the machine guns are fired so that the efiiciency thereof is affected considerably by the displacement of the helicopter through the recoil forces.

It is therefore the principal object of this invention to provide a machine gun having an integral mechanical system for reducing considerably the recoil forces applied to the trunnions on which the machine gun is mounted to a carriage as, for instance, a helicopter.

It is a more specific object of this invention to provide a machine gun having a recoiling mass which is seared each cycle to a nonrecoiling mass against the force of loaded buffer springs. At the appropriate time before the chambered cartridge is fired, the sears are actuated to release the recoiling mass for forward displacement so as to apply the load of the buffer springs against the recoil force driving the recoiling mass rearwardly, and thereby considerably reduce the recoil force transmitted to the trunnions.

It is a further object of this invention to provide such a machine gun in which the sears are arranged to hold the recoiling mass stationary, respective to the nonrecoiling mount, while a cartridge is fed from a feeder mechanism carried by the nonrecoiling mounting assembly to a battery position in the seared recoiling mass, and the previously fired cartridge case is ejected.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the acompanying drawings in which:

FIG. 1 is a side view of a machine gun complete with the recoil force reducing system of this invention and shows the recoiling mass seared in its rearward position, against the force of the loaded butter springs, to the nonrecoiling mount;

nited States Patent FIG. 2 is a top view of the machine gun showing the scars blocked in their searing positions with parts of the reeoiling mass structure, which cooperate with the nonrecoiling mass, being shown in phantom;

FIG. 3 is a view taken along line 3-3 of FIG. 1;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a view similar to FIG. 4 but shows the sear locks actuated to release the scars;

FIG. 6 is a view taken along line 6-6 of FIG. 5;

FIG. 7 is a view taken along line '7-7 of FIG. 5;

FIG. 8 is a view taken along line 88 of FIG. 5;

FIG. 9 is a schematic view of the machine gun showing the recoiling mass seared in its rearward position to the nonrecoiling mass with the recoiling mass being represented by heavy outline;

FIG. 9a is a view similar to FIG. 9 but shows the sears released and the barrel located between its forward loading and rearward battery positions during the rearward stroke there;

FIG. 9b is a view similar to FIG. 9a but shows the relationship of the parts at the instant the machine gun is fired and the ear-released recoiling mass is moving forwardly under the influence of the loaded buffer springs;

FIG. is a view similar to FIG. 912 but shows the relationship of the parts when the barrel is in its forward stroke to the loading position and the recoiling mass is .researed in its rearward position to the nonrecoiling mass, for ejection of the fired case and the feeding of a fresh cartridge to battery position.

Shown in the figures is a machine gun 12 having a nonrecoiling mass 1d and a recoiling mass 14 which is mounted thereon for longitudinal reciprocation. Recoiling mass 14 includes a receiver assembly 18 which slidingly supports a barrel 20 disposed for axial displacement respective thereto, a drum-cam assembly 22 arranged for actuating the barrel between a forward loading position and a rearward firing position, and a firing mechanism (not shown) which is actuated by the drum-cam for firing a cartridge 24 when located at a battery position in the receiver assembly and chambered in the barrel.

Nonrecoiling mass 16 includes a mount assembly 26 which carries an electric motor drive assembly 28 for driving drum-cam assembly 22, and a feeder mechanism 36 for delivering cartridge 24 to the battery osition in receiver assembly 18. Feeder mechanism 30 is driven by motor drive assembly 28 in synchronism with th actuation of barrel 26 so as to feed cartridge 24 to battery position in receiver assembly 13 when the breech end of the barrel is clear of the nose of the cartridge.

Referring to FIG. 2, mount assembly 26 includes a cradle 32 which slidingly mounts receiver assembly 18 for longitudinal displacement between a forward and a rearward position, and a pair of double-acting buffers 34 which are respectively mounted on opposite sides of the cradle. Buffers 34 are of conventional design and each includes a moving member as which is acted upon by opposing springs 38 and 4d and which has a protruding arm 4-2 connected to receiver assembly 18. Buffers 34 are so arranged that when receiver assembly 18 is in its rearward position springs 40 are loaded to a redetermined force. Mounting trunnions 43 are provided on cradle 32 for mounting machine gun 12 on a carriage (not shown).

Receiver assembly 18 is releasably held adjacent its rearward position by a pair of sears 44 respectively mounted on opposite sides of cradle 32. Sears 44, as hereinafter explained, snap into searing positions for engagement with cooperating lugs 46 on receiver assembly 18 when the receiver assembly is adjacent its rearward position,

thereby holding the receiver assembly against the load of the compressively energized springs 40.

Considerable force is applied against sears 44 when they stop forward displacement of receiver assembly 18, therefore they are soft mounted, as described hereinafter, to cushion the impact applied thereagainst by the receiver assembly.

Cradle 32 is provided at its rear end with a pair of vertically extending sides 48 in each of which there is provided a longitudinally extending slot 50 for receiving one of the sears 44. Each of the sears 44 is mounted on a vertically disposed shaft 52 which is rotatingly received by a pair of coaxially related holes 54 vertically disposed in the related side 48 so that the sears can swing inwardly to a searing position and outwardly to a disengaged position. Holes 54 are elongated longitudinally so that the related shafts 52 have limited longitudinal displacement therein relative to cradle 32. Shafts 52 are held resiliently against the rear end of the respective holes 54 by a cooperating pair of spring pressed plungers 56 which cushion the forward displacement of the related shafts in the holes 54, and therefore sears 44, when the sears are engaged by the forwardly pressed receiver assembly 18.

Sears 44 are each biased inwardly to its searing position by a cooperating spring 58 and each is secured in the searing position by a lock 60. Each of the locks 60 is slidingly mounted in a vertically disposed T-slot 62 formed in the respective one of the sides 48 so as to be slidable in back of the respective sear 44 to block pivotal displacement thereof from the searing position. Locks 60 are connected by a transverse rod 64, as seen in FIG. 6, which is acted upon by a solenoid 66 through a lever 67 for raising both locks from in back of the related sears 44 to their release positions.

Locks 60 are biased downwardly in back sears 44 to their blocking positions by a pair of springs 65 which act against lever 67. When locks 60 are raised to their release positions, sears 44 are snapped thereunder as hereinafter described to their disengaging position and thereby the sears hold the locks in their release positions when solenoid 66 is deenergized. The contacting surfaces of locks 60 and sears 44, shown respectively at 69 and 71 in FIG. 7, are angularly designed to assure that the sears cannot bounce back when actuated to their searing positions by permitting the inertia of the locks to be overcome before final disengagement of the sears therefrom.

Solenoid 66 is controlled by a microswitch 68 mounted on the front portion of cradle 32 for cooperation with a cam actuator 70 on barrel 20, as best shown in FIG. 1. Cam actuator 70 and microswitch 68 are so arranged that solenoid 66 is energized to raise locks 60 to their release positions when barrel 20 is adjacent its firing position during the rearward travel thereof.

Sears 44 are actuated to their disengaging positions through the camming contact of surfaces 72 on the sears with surfaces 74 on lugs 46, which surfaces are so angularly designed that the forward displacement of receiver assembly 18 relative to the sears 14 displaces the sears to their disengaging positions. Thus, when locks 60 are raised to their release positions, unblocking sears 44, the sears are immediately swung outwardly to their disengaging positions, freeing receiver assembly 18 for forward displacement by the loaded springs 40 to largely overcome the forces imparted to the receiver assembly when the chambered cartridge 24 is fired. The energy in springs 40, at the time of discharge of cartridge 24 must be less than the recoil force imparted to receiver assembly 18 so that sufficient recoil force remains to drive the receiver assembly 18 back to its rearward position for reenergizing springs 40 and reengagement by sears 44 for the next firing cycle.

If cartridge 24 should misfire, the forward propulsion of receiver assembly 18 is resiliently stopped by springs 38 and the receiver assembly is actuated rearwardly to reenergize springs 40 and be reengaged by sears 44 through a charger mechanism 76.

OPERATION At the commencement of a firing cycle, receiver assembly 18 is seared to mount assembly 26, a cartridge 24 is located in battery position and electric motor 28 is energized to rotate drum-cam assembly 22 which moves barrel 20 rearwardly for envelopment of the cartridge. As barrel 20 moves rearwardly, cam actuator 70 contacts microswitch 68, when the barrel is adjacent its rearward firing position, to energize solenoid 66 which raises locks 60 to free sears 44 for release of receiver assembly 18 just before the enveloped cartridge 24 is discharged by the firing mechanism (not shown). The energy of the loaded springs 40 which drives the released receiver assembly 18 forwardly acts to largely overcome the recoil force transmitted to the receiver assembly by the discharge of cartridge 24 so that the force with which the receiver assembly is actuated rearwardly is considerably less than would have been transmitted to trunnions v 43 without the benefit of mount assembly 26.

After cartridge 24 is fired, barrel 20 is actuated forwardly from its firing to its loading position by the continued rotation of drum-cam assembly 22. During this time, receiver assembly 18 is driven back to its rearward position to be researed to mount assembly 26 and indexed respective thereto so that when the barrel passes through its loading position the receiver assembly is fixed to mount assembly 26 to facilitate the ejection of the fired case by a mechanism (not shown), and the feeding of a fresh cartridge to battery position by the feeder mechanism.

In one machine gun 12 designed according to this invention, recoiling mass 14 weighed pounds, springs 40 had a load of 1000 pounds when the recoiling mass was seared to nonrecoiling mass 16 and an approximately 800 pound load, moving the recoiling mass to 7 /2 feet per second, when cartridge 24 was fired. In such machine gun, a load of not more than 1200 pounds was transmitted to trunnions 43 when cartridge 24 was fired. With receiver assembly 18 solidly mounted on cradle 32 the load transmitted to trunnions 43, when the cartridge was fired, was 12,000 pounds.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. A machine gun including a nonrecoiling mass having a mount assembly; a recoiling mass having a receiver assembly slidingly mounted on said mount assembly to provide for reciprocation of said recoiling mass between a forward and a rearward position; a barrel disposed for reciprocation in said receiver between a forward loading position and a rearward firing position; said recoiling mass being displaceable to the rearward position by discharge of a cartridge in said barrel; an energy storing device arranged to be energized by displacement of said recoiling mass by the cartridge discharge and to apply the stored energy against said recoiling mass in a forward direction;

sear means for releasably holding said recoiling mass adjacent the rearward position against displacement by the stored energy in said device each firing cycle, said sear means including a pair of sears respectively mounted on opposite sides of said mount assembly for pivotal displacement respective to a cooperating pair of lugs on said receiver assembly, a surface on each of said sears disposed for contact with a mating surface on the cooperating ones of said lugs, said surfaces on said sears and said lugs being angularly formed so that when in fixed contact said recoiling mass is held thereby adjacent the rearward position and so that forward displacement of said recoiling mass relative to said sears rotates said sears to a release position clear of said lugs, and a pair of locks disposed for releasably blocking pivotal displacement of said sears to maintain said surfaces on said sears and said mating surfaces on said lugs in fixed contact; and means for actuating said locks to release said sears and free said recoiling mass in time to apply the energy in said device against the energy imparted to said recoiling mass by discharge of the cartridge before said recoiling mass reaches the forward position for reducing the energy eflFective against said nonrecoiling mass, said means for actuating said locks including an electric solenoid arranged when energized to actuate said locks from positions blocking displacement of said sears, a microswitch mounted on said mount assembly and arranged to electrically energize said solenoid, and a cam actuator located on said barrel for engagement with said microswitch to energize said solenoid when said barrel is adjacent the firing position during rearward travel thereof so that the energy in said device drives said recoiling mass forwardly when the cartridge is discharged.

2. The machine gun as defined in claim ll wherein said device is provided with means for cushioning the forward displacement of said recoiling mass by the energy in said device when the cartridge in the battery position does not fire.

3. A machine gun including a nonrecoiling mass, a recoiling mass mounted on said nonrecoiling mass for sliding displacement relative thereto by discharge of a cartridge at a battery position in the recoiling mass, a barrel mounted in said recoiling mass for reciprocation relative thereto between a forward loading position and a rearward position for enveloping for discharge the cartridge when located in the battery position, a feeder mechanism mounted on said nonrecoiling mass and arranged to deliver the cartridge to the battery position, a sear device for releasably holding said recoiling mass each firing cycle to said nonrecoiling mass to permit uninterrupted movement of said cartridge by said feeder mechanism to the battery position, and means actuated by said barrel for releasing said sear device to free said recoiling mass from said nonrecoiling mass.

4. A machine gun including a nonrecoiling mass, a recoiling mass mounted on said nonrecoiling mass for sliding displacement relative thereto between a forward and a rearward position, said recoiling mass being displaceable to the rearward position by a force produced by discharge of a cartridge therein, a device for storing energy and for applying the energy against said recoiling mass in a forward direction, sear means for releasably holding said recoiling mass adjacent the rearward position against displacement by the energy in said device each firing cycle, means for releasing said sear means to free said recoiling mass in time to apply the energy in said device against the force imparted to said recoiling mass by discharge of the cartridge before said recoiling mass reaches the forward position to reduce the force effective against said nonrecoiling mass, a barrel mounted in said recoiling mass for reciprocation between a forward loading position and a rearward firing position, and cam means on said barrel arranged in cooperation with said means for releasing said sear means to free said recoiling mass from said nonrecoiling mass during rearward travel of said barrel and when adjacent the firing position.

References Qited by the Examiner UNITED STATES PATENTS 891,778 6/1908 Mertens 89-44 2,249,310 7/1941 Braun et al. 89-42 2,536,997 1/1951 Lippert et al. 89-l90 2,701,963 2/1955 Balleisen et al. 8944 3,182,555 5/1965 Rocha 89-33 3,242,812 3/1966 liaillard 89-44 BENJAMIN A. BORCHLET, Primary Examiner. S. C. BENTLEY, Assistant Examiner. 

1. A MACHINE GUN INCLUDING A NONRECOILING MASS HAVING A MOUNT ASSEMBLY; A RECOILING MASS HAVING A RECEIVER ASSEMBLY SLIDINGLY MOUNTED ON SAID MOUNT ASSEMBLY TO PROVIDE FOR RECIPROCATION OF SAID RECOILING MASS BETWEEN A FORWARD AND A REARWARD POSITION; A BARREL DISPOSED FOR RECIPROCATION IN SAID RECEIVER BETWEEN A FORWARD LOADING POSITION AND A REARWARD FIRING POSITION; SAID RECOILING MASS BEING DISPLACEABLE TO THE REARWARD POSITION BY DISCHARGE OF A CARTRIDGE IN SAID BARREL; AN ENERGY STORING DEVICE ARRANGED TO BE ENERGIZED BY DISPLACEMENT OF SAID RECOILING MASS BY THE CARTRIDGE DISCHARGE AND TO APPLY THE STORED ENERGY AGAINST SAID RECOILING MASS IN A FORWARD DIRECTION; SEAR MEANS FOR RELEASABLY HOLDING SAID RECOILING MASS ADJACENT THE REARWARD POSITION AGAINST DISPLACEMENT BY THE STORED ENERGY IN SAID DEVICE EACH FIRING CYCLE, SAID SEAR MEANS INCLUDING A PAIR OF SEARS RESPECTIVELY MOUNTED ON OPPOSITE SIDES OF SAID MOUNT ASSEMBLY FOR PIVOTAL DISPLACEMENT RESPECTIVE TO A COOPERATING PAIR OF LUGS ON SAID RECEIVER ASSEMBLY, A SURFACE ON EACH OF SAID SEARS DISPOSED OF SAID LUGS, SAID SURFACES ON SAID SEARS AND SAID LUGS BEING FOR CONTACT WITH A MATING SURFACE ON THE COOPERATING ONES ANGULARLY FORMED SO THAT WHEN IN FIXED CONTACT SAID RECOILING MASS IS HELD THEREBY ADJACENT THE REARWARD POSITION AND SO THAT FORWARD DISPLACEMENT OF SAID RECOILING 